1. Field of Use
This invention relates to detection apparatus and more particularly to apparatus capable of verifying the correctness of binary coded information.
2. Prior Art
It is well known to provide duplicate circuits together with compare circuits for duplicating the performance of a given operation and comparing both results in order to determine whether the operation was performed properly. It has been found that this type of checking arrangement is extremely costly. More importantly, such arrangements are not usually able to detect whether the particular code being checked is a "valid" or "legal" code.
The prior art has also provided arrangements for detecting errors produced by hardware failures occurring in a decoder circuit. While such arrangements reduces the redundancy of circuits required for performing verification, they also reduce the circuits capability of verifying the correctness of the binary coded signals. More importantly, arrangements of these types are also not normally able to detect whether the code is a valid code.
Accordingly, it is an object of the present invention to provide improved error detecting apparatus which utilizes a minimum of circuits for verifying the correctness of binary coded information signals.
It is a further object of the present invention to provide error detecting apparatus which also verifies the correctness of the code in addition to detecting the occurrence of hardware failures in the detection apparatus.